I unfortunately blew the mainboard of my FT-857d in my Ridgeline truck set up. Not sure how that happened. The set-up ran great for nearly 3 years but te 857D was getting up there in age. Quoted $700 to repair by Yeasu so going in the parts pile. It's going to be a while before I can afford a new rig for the truck so looking to put my idle IC-706MK2G into service until I can afford a new rig. What's the best way to key the SG-500 with the 706? With the 857D I customized a data cable to bring the PTT to ground. Is that the way to go with the Icom?ThanksBob, W8NYY

The 706 will sink up to 20 mils. The keying circuit in the SG500 draws just 2 mils. Pin 3 of the accessory socket is HSEND, and goes low anytime the radio is keyed. that connects to the PTT on the green header plug. You should run a ground too. if you set the filter switch to Auto, and the PTT to manual, you're in business.

By the way, the 13 pin Kenwood accessory plug it the same one as Icom uses, but without the pigtails. HRO and AES both carry them, for about $7.

You can go to my wen site, and read the Amplifier Care & Feeding article for more info.

Thanks Alan. It appears that the data plug on the 706 is identical to the FT-857d. Couldn't I use the data port to pull the PTT to ground as I did with the Yeasu? It would be easier ti reuse the cable I made up for the 857d if I could versus making up a new cable for the acc output.Bob, w8nyy

The jack on the back of the Yaesu is an 8 pin, special DIN. The one on the back of the 706 is a 13 pin. The plug with comes with the Icom has a pigtail with stripped wires. Some of those you do not want to short out! That is why I suggested using a new one without the pigtail.

Alan,I've never had the occasion to point out that you are wrong but in this case I'm afraid you are. Please refer to page 37 of the Icom 706MK2G manual where it states:PIN #/NAME DESCRIPTION1 DATA IN Communication data input.2 GND Ground for DATA IN, DATA OUT and AF OUT.3 PTTP Transmits when grounded.4 DATA OUT Outputs 9600 bps receive data.5 AF OUT Outputs 1200 bps receive data.6 SQ Squelch output. Goes to ground when squelch opens.

On page 33 of the FT-856d manual, while they do not refer to the pins by number and the picture is inverted as compared to the IC-706MK2G, their pin assignment is referred to as:

I stand corrected. I was looking at the CAT port on page 32, and forgot all about the other port shown on page 33. This is one case where thing just work out, unless the unused pins connect to something.

I was also corrected by AD5X recently about the TX D pin being able to handle 3.5 amp or whatever is was (is). You just can't know all of the details, of everything out there.

I have schematics, and owners' manuals on both radios should you need them. Problem is, they're rally big data wise. I think the Icom one is about 30 MB.

This is sort of off the subject, but if you really want to get into some esoterica, ask some one what the jack on the bottom of the radio is used for.

No problem Alan. I have learned a ton from you over the years and attribute the excellent mobile set up that I have to the learnings I received from you and your site. It's certainly a rare occasion that you may have missed something but you're right that there is just so much out there to know that it's impossible to keep up on everything. Still I will continue to check with you and your site on things I'm not sure of just to check myself. You've always been a great resource and quick with a response and I do appreciate it.73,Bob, W8NYY

Both the 857, and the 706 are getting very long in tooth. Even the 7000 as good as it is, is getting long in tooth too.

If you believe in rumors, the 7000 will soon be a 7010, replete with selectable roofing filters, and an upgraded DSP. I suspect the DSP, and roofing filters will be the same ilk as the new IC7410.What Yaesu's answer will be is anyone's guess.

If there is any puzzles to be answered, it is the standard feature set of the new Alinco XR8. I just wonder what they were thinking?

Alan,You make a good point about the rigs being "long in the tooth" and thus my reluctance to spend on something new for now when I have an additional 706 I can utilize.I did try sending you a personal email but it bounced. Your ARRL.Net address isn't accepting my emails even though I am not using Hotmail or Gmail. Here's what I sent you:

Thanks for the feedback relative to my options for keying the SG-500 with my IC-706MK2G. After careful reconsideration, I have decided to go with using the acc port output via the HSEND pin as you originally suggested. With the 13pin accessory plug they provide with the rig, it's simple enough to make up a control cable to run to the PTT and GND input on the SG-500 running from pin 3 HSEND and pin 2 GND.

My question though is relative to your statement on your website under the Amplifier Commercial section:

"The keying voltage 4.3 volts at 2 mils. This means it can be switched directly by an Icom IC-706, or IC-7000 (and select Yaesu models like the FT857) via the HSEND line, although a keying interface is recommended."

I keyed the SG-500 directly with my FT-857d but ultimately did lose my 857d due to a fried main board. I don't know if the cause had anything at all to do with my keying of the SG-500 and in fact when the radio went I had my Tarheel antenna down for cleaning and due to snow in the bed so hadn't been operating HF for at least a month before the radio went.

Still I am fixed on your statement that a keying interface is recommended. An investment of $69 for an AR-704 is not a deal breaker for me and if you feel it makes better sense to insert that in my setup, does it make sense? I'm not crazy about another do-dad in the mobile chain but if it's a worthy investment, I'll make room. I'd appreciate your viewpoint on your comment above and if a key is recommended, would the AR-704 be your choice.

By the way, I can't tell you how many times I had to defend with my electrician and electrical engineer friends as to why I don't have an Isolator installed instead of having my Optima Red Top in parallel with the main battery. LOL. I have quoted you often.

This is bringing and old thread back to life, but I'm curious as to your answer to Bob's question about the keying interface. I'm going to build an interconnect tonight to bridge my SG-500 with my IC-706MKIIG and now I'm wondering if I should wait. Was the keying interface recommended?

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